Conversion and treatment of mineral oils



June 21, 1938. i A E PEW, JR

' CONVERSION AND TREATMENT OF MINERAL. OILS 'Filed Dec. 16, 1935 l Patented June 21, 1938 UNITED STATES CONVERSION AND TREATMENT OF MIN- EBAL OILS Arthur E. Pew, Jr., Bryn Mawr, Pa., assigner, byv mesne assignments, to Houdry Process Corporation, Wilmington, Delaware Del., a corporation of Application December 16, 1935, Serial No. 54,641

2 Claims.

This invention relates to processes for the conversion, transformation, modification, refining or other treatment of hydrocarbons including mineral oils from any source and their distillates 5 and residues. More particularly it relates to a once-through operation involving aseries of transforming or treating steps. In certain aspects. it may be considered as embodying improvements upon or further developments of the invention set forth in the copending application of Eugene J. Houdry,'Serial No. 512,466, filed January 30, 1931, renewed on October 18, 1934 and refiled as Serial No. 71,341 on March 27, 1936.

One object of the invention is to produce finlshed products substantially without heat input into the charge after the heating of the same for the first step. Another object is to effect a progressive reduction in the temperature of the stream from step to step. Another object is to drop out of the stream at least the heaviest components at the times of reduction of temperature. Another object is to subject all of the desirable products to desulphurization and the lighter ones to refining as well. Other objects will be apparent from the detailed description which follows.

Instead of subjecting the hydrocarbon stream after the conversion or transforming step to fracj tionatlon so that the subsequent desulphurizing and refining steps are applied only.to the light overhead material (as contemplated in oertain forms of the invention disclosed in the aforesaid copending application), the present inventionlinvolves progressive or step-by-step reductions in the temperature of the stream so that the heat input into the charge for'the` rst step carries through the subsequent steps. By preference, the temperature 'reductions are sufficient to condense the heavier components of the stream 40 and these are withdrawn before the stream goes on into the next treating zone. Hence there is a partial cooling of the stream and removal of condensate before one, and preferably before both the desulphurizing step and the refining step but, in each instance, the vremainder of-the stream is left at a proper temperature for the next treating step.

In order to illustrate the invention, a preferred application or embodiment is diagrammatically indicated by the flow chart which forms the only figure on the accompanying drawing.

As indicated, a charging material, such as heavy.l hydrocarbons, derived from petroleum or from the destructive distillation of bitumens, or

from a, conversion of such materials in the gas (Cl. 19E-52) oil boiling range or higher, is sent, preferably in preheated condition, by line 2, into a suitable heater such as a pipe still 4.` `The charge, then heatedtol conversion temperature, is sent by line 5 into a flash pot 5a forthe removal of unvaporizedby a suitable catalytic mass, a. good reaction range is 760 to 900 F. If the reaction is entirely thermal in character, the temperature range may be from 800 to l100 F., or higher. The stream of transformed material passes from vessel 6 to a purifying crdcsulphurizing vessel 8 by a connecting line 1, and, intermediate these two reaction zones, there is a zone of temperature reduction or a condensing `zone in which the stream is reduced in temperature by passing through any suitable heat exchange equipment, indicated at 9, the drop in temperature being preferably'sufl'lcient to condense out at least the heaviest components of the stream, which are withdrawn by line l0 to a suitable storage tank Il. The 'remainder or vapor phase portion of the stream passes at reaction temperature into vessel 8, whereit is subjected to a desulphurizing or other purifying operation in contact with a desulphurizing Contact material in the temperature range of 600 to 775 F. The

purified material passes from vessel 8 by line I2, which connects with a refining vessel I3, the -stream of puried material, however, being reduced in temperature by its passage through suitable heat exchange equipment indicated at I4, the drop in temperature of the stream being sufficient to condense out at least the then heavier or higher boiling material components of the stream which are Withdrawn as desulphurized or purified oil, e. g. a gas oil by line l5 for storage in tank I6. The remainder or vapor phase portion of the stream enters vessel i3 at reaction temperature, where it is subjected to a refining and chemical stabilizing and polymerizing reaction, preferably lin the presence of solid adsorptive `contact material, 4the reaction being effected in the range of 430 to 620 F. Tho stream of refined material issuing from reaction chamber i3 passes, by line l1, into a fractionating tower I8, wherein end point gasoline vapors, fixed gas, and extraneous gaseous material may be taken overhead by line I9, while the heavier or higher boiling hydrocarbons, e. g. gas oil are condensed and withdrawn from the bottom of the tower by line 20 for storage in tank 2I. Lighter condensed hydrocarbons may be withdrawn from the tower in a side stream by line '28a for storage in tank 2Ia. The overhead stream in line I8 is sent through a condenser 22 and thence, by line 23, through a separator 24, from which clean gas may be withdrawn through an upper outlet 25, water by a lower outlet 28, and rened and stabilized end point gasoline by an intermediate outlet line 21 leading to storage tank 2.8. The operation of tower I8 may be regulated in a conventional manner by recirculating therein condensed gasoline from separator 24 or tank 28 through suitable connections (notshown).

It is to be understood that the present invention contemplates the multistage treating oper- -ation on the charging stock substantially without heat input other than that furnished by i heater or still 4. 'I'he temperature of the continuous stream of material undergoing treatment, after leaving the first or converting zone, is reduced, and the composition of the stream is modified before each of the subsequent treating steps. Removalof heat from the stream may be effected by any suitable means and by any known or desired type and arrangement .of equipment. 'I'he heat thus remo'ved may be utilized to preheat the charge, and this is indicated in the accompanying flow chart, wherein the fresh feed is shown as passing by line 29 through heat exchange means I4, thence by line 30 through heat exchange means-8, and thence into line 2 lead ing to still 4.

lWhile the conversion or vtransformation effected in the first zone may be either thermal or catalytic, it is, by preference, catalytic, as indicated also in the aforesaid Houdry application. Infact, it is preferred, but not essential, that a contact treatment take place in each of reaction chambers 8, 8, and I3. The catalytic or contact masses may be composed of any material capable of effecting the desired reactions within the specified temperature ranges. 'The masses, however, are preferably in the form of lumps, fragments or molded pieces, so as to be capable of regeneration in situ. 'Iwo or more reaction chambers are intended to be utilized in each zone, in order that the process may operate continuously with the converters in each zone alternately on stream and in regeneration. Any metals or metallic compounds having the desired selective or adsorptive activity may be used forv the various A masses, and, if desired, these metals or metallic compounds may be incorporated, in finely divided form, into or upon porousv carriers which are themselves either catalytically active or inert. Suitable carriers include those formed of china. clay, pumice, fullers earth. diatomaceous earth, and like clayey materials. A desirable carrier of this general -type is disclosed in U. S. Patent No. 1,818,403, issued to A. Joseph on August 11, 1931. An inert or relatively inert carrier is preferably used in vessel 8 for the desuiphurizing or purifying reaction, the bodies of porous earthenware or other support containing or carrying upon and within the same some metalor metallic compound having an ailinity for mineral or other combined sulphur, such as nickel, cobalt, or copper. One method of impregnation is by soaking the support in the nitrate or other salt of the metal, and then converting the nitrate or other salt to an oxide, as by heating. For the catalytic masses in vessels 8 and I8, active or activated clayey materials, with or without the addition of other adsorptive materials such as metals or metallic compounds, maybe utilized. Such active basic material may comprisenatural or artificial blends of silica and alumina produced in various ways, one way being by suitablev acid or other chemical treatment of naturally occurring clays or blends of clays. The contact mass for the ilrst or conversion zone may comprise molded pieces of activated hydrosilicate of alumina of suitably controlled silica to alumina ratio. The contact mass for the last or refining and stabilizing zone may comprise the same or similar material with 10% or less oi nickel, copper or cobalt in metallic or oxide form. Catalysts of this general type arev disclosed in the 'copending application of E. J. Houdry, Serial No. 600,581, filed March 23, 1932 which issued on May 4, 1937 as Patent No. 2,078,945.

The operating conditions will be selected to suit the charging material and the type of conversion desired in the first zone. For a straight-through catalytic or contact operation in all zones, with a charging material comprising a deep gas oil cut with a portion of the bottoms from crude oil, a good operation consists in heating the charge in stili 4 to 830 F. or slightly thereabove, conducting the catalytic transforming operation in converter 8 at 825 to 850 F., and reducing the temperature of the stream in heat exchange equipment 8 to remove a certain amount of the heavier material, so that the stream enters the desuiphurizing zone in the range of 650 to 700 F., with the contact operation taking place at about 675 F. The stream issuing from the desuiphurizing zone is reduced in heat exchanger I4 to about 450 to 500 F., and the refining land chemical stabilizing andpolymerizing operation is conducted in .con-

verter Il in the range of 430 to 500 F., or at about v475 F. It is to be understood, however, that the temperatures may be adjusted within the specied ranges as desired or required to suit the charging material or the particular finished products to beproduced. and that the. process may be operated at subatmospheric, atmospheric, or superatmospheric pressure. By operating under pressure, removal of condensate at heat exchangers 8 and I4 is facilitated.

Because of the wide variance in the composition of different hydrocarbon feed stocks, denite feed rates cannot be given. However, where a contact material or catalyst is used in each of vessels 8,',8 and I3, in general the rates of feed on the conversion catalyst in vessel 8 may vary, for example, from, 10 to 30 liters of charge per hour per 20 liters of catalyst (i. e. 10/20 to 30/20) -Much higher rates can normally be used in the refining catalyst in vessel I3, as, for example, 20/20 to 200/20 and as high or still higher rates tact mass. An illustrative operation for gasoline production` involves a rate of 18/20 inthe conversion chamber 8, 100/20 in the desuiphurizing chamber 8, and /20 in thereiinlng chamber I3.

From the above, it is apparent that the present invention involves an operation in which material'to be transformed is sent in a continuous stream through a series of reaction zones, with the removal of heat and/or a portion of the stream after each zone, the material being removed because itis already a ilnished product or because it isundesirable to subject it to treatment sov - may often be employed in the desuiphurizing conin the succeeding zones. Thus, for example, in the loperation set forth specifically in the second preceding paragraph, the material drawn oiT into storage tank Il will be very heavy hydrocarbons not transformed in the preceding crack- .ing or converting stage and which are suitable for recharge in a subsequent run, the material withdrawn into tank I6 will be purified or desulphurized oil in the gas oil boiling range suitable for use as finished product as Diesel oil or domestic fuel oil, the materials taken out of fractionating tower I8 will also be nished products comprising a still more completely refined oil in the gas oil range in tank 2| and refined kerosene and `heavy naphthas in tank 2m, and, as iinal products after condensation from separator 24, there are obtained refined and stabilized end point gasoline and highly puried clean hydrocarbon gases. i

I claim as my invention:

,1. In the production of refined lower boiling hydrocarbons including those within the light motor fuel or gasoline boiling range in a continuous straight-through operation from a composte hydrocarbon charge boiling to substantial extent above the gasoline boiling range, the steps of process which comprise heating and passing the hydrocarbon charge through a confined conversion-zone containing an adsorptive catalytic material maintained at a temperature substantially within the range of760 to 900 F., continuously removing fluid products from said conversion zone and passing them through a condensing zone, continuouslyl separating to substantial extent higher boiling components which condense' therein at temperatures above approximately 650 F. from the remaining fluid."

products from said desulphurizing zone and' passing them through a condensing zone, separating to a substantial extent liquid components which condense in the zone last-mentioned at temperaturesabove approximately 450l F. From the remaining lower boiling components of the fluid products 'from the desulphurizing zone, passing said lower boiling vaporous components in the absence of said liquid components through a confined chemical stabilizing and refining zone containing an adsorptive catalytic material comprising essentially an active silicious material having incorporated therewith a relatively small proportion of a metalliferous material capable of reacting with inorganic sulphur in the vapors to form a sulphur compound of the metal, the lastmentioned catalytic material being maintained at a temperature substantially within the range of 430 to 620 F., withdrawing fluid products from said refining zone, and fractionating the last-mentioned products to separate a light motor fuel fraction of high quality from remaining hydrocarbons.

2. In the production of refined lower boiling hydrocarbons including those within the light motor fuel or gasoline boiling range in a continuous straight-through operation from a composite hydrocarbon charge boiling to substantial extent above the gasoline boiling range, the steps of process which comprise heating and passing.

the hydrocarbon charge through a conned conversion zone under conditions so as-to effect a cracking or production of lower boiling hydrocarbons from the higher boiling hydrocarbons, said conversion zone being maintained within the temperature range of 760` to 1l00 F., continuously removing fluid products from said conversion zone and passing them through a condensing Zone, continuously separating at least a substantial proportion of the higher boiling components thereof which condense therein at temperatures above those of the order of 650 to '700 F. from the remaining vaporous products of conversion, passing said remaining vaporous lly withdrawing fluid products from said desulphurizing zone-and passing them through a condensing zone, separating to a substantial extent liquid components which condense in the zone last-mentioned at temperatures above those of the order of 450 to 500 F. from the remaining lower boiling. components of the fluid products yfrom the desulphurizing zone, passing said lower boiling vaporous components in the substantial absence of said liquid components through a confined chemical stabilizing an'd refining zone containing an adsorptive catalytic material comprising essentially an active blend of silica and alumina, the last-mentioned catalytic material being maintained at a temperature substantially within the range of 430 to 620 F., withdrawing fluid products from said refining zone, and fractionating the last-mentioned products to separate a gasoline fraction of high quality from remaining hydrocarbons.

ARTHUR E. PEW, Jn. 

